Clostridium difficile infection

December 16, 2014

Zachary Rubin, MDUCLA Infectious Diseases

UCLA Clinical Epidemiology & Infection PreventionMattel Children’s Hospital UCLA

Objectives• Review C difficile epidemiology and recent changes in

trends• Understand the pathophysiology and clinical spectrum of

C difficile • Summarize C difficile diagnostic testing and treatment

options• Review the infection prevention fundamentals of C difficile

Heron et al. Natl Vital Stat Rep 2009;57(14). Available at http://www.cdc.gov/nchs/data/nvsr/nvsr57/nvsr57_14.pdf

Age-Adjusted Death Rate* for Enterocolitis Due to C. difficile, 1999–2006

*Per

100

,000

US

stan

dard

pop

ulat

ion Female

0

0.5

1.0

1.5

2.0

2.5

1999 2003

Rat

e

2000 20042001 20052002 2006Year

Male

WhiteBlackEntire US population

CDI Epidemiology

Zilberger et al EID 2010; 16: 604; Sammons et al CID, 2013; 57: 1

• 53% increase in infection rates 2001-2006

• Not associated with increase mortality or severe morbidity such as colectomy or toxic megacolon

CDI Differs by Age Group

Zilberg et al EID 2010; 16: 604

• 10 cases of severe peripartum CDAD• 23 cases of severe community-associated CDAD (CA-CDAD)• 11 pediatric cases, all community-associated

• Approximately 1/3 without prior antimicrobial use

• Thought to be related to emergence of new strain, NAP1/027

Courtesy Romney Humphries, UCLA microbiologyMMWR Morbidity Mortality Wkly Rep 2005;54:1201–5.

Why is CDI increasing?

NAP1/B1/027 Strain• Hypervirulent C difficile strain

• Seems to transmit more effectively• Associated with fluoroquinolone resistance

• Possesses two standard toxins and an additional binary toxin• Hyperproduce toxin by more than a factor of 10

• Represent 10-20% of toxigenic strains in children• Data inconclusive about association between NAP1 and more severe clinical presentations

Tolzis et al J Peds 2009; 154: 607Kelly et al NEJM 2008; 359:18 Warny et al Lancet 2005; 366: 1079

Lack of Antibiotic Exposure• Number of pediatric studies highlight that a subset of children

with CDI have no antibiotic exposure• 24-44%

• Limitations of published studies• How distinguish between colonization and infection?• How determine whether some patients seen in a different medical system?

• How define antibiotic exposure? How determine if someone has received antibiotics?

Sandora et al, PIDJ 2011; 7: 580Samady et al J Hosp Med 2013, epublished

Pooled CDI Rates$, ICUs RRUCMC, Nov 2013 - Oct 2014

$All rates are CDI rate per 10,000 patient days1CDPH Target Rate = 9.4/10,000, http://www.cdph.ca.gov/programs/hai/Documents

3 4 3 6 4 5 1 3 2 12 3 2

6.709.11

6.94

15.92

9.4412.03

2.34

7.57

4.80

27.81

7.334.77

0

2

4

6

8

10

12

14

0.0

5.0

10.0

15.0

20.0

25.0

30.0

# of Infections

N-13 D-13 J-14 F-14 M-14 A-14 M-14 J-14 J-14 A-14 S-14 O-14C-Diffs 3 4 3 6 4 5 1 3 2 12 3 2C-Diff Rate 6.70 9.11 6.94 15.92 9.44 12.03 2.34 7.57 4.80 27.81 7.33 4.77

Rate# infections per10,000 Pt Days

C-Diffs C-Diff Rate

Pooled CDI Rates$, ACUs RRUCMC, Nov 2013 - Oct 2014

$All rates are CDI rate per 10,000 patient days1CDPH Target Rate = 9.4/10,000, http://www.cdph.ca.gov/programs/hai/Documents

2 4 8 11 11 8 5 13 8 16 11 13

3.13

6.22

12.85

20.0518.04

12.50

7.63

19.97

9.23

19.17

13.21

19.46

0

2

4

6

8

10

12

14

16

18

0.0

5.0

10.0

15.0

20.0

25.0

# of Infections

N-13 D-13 J-14 F-14 M-14 A-14 M-14 J-14 J-14 A-14 S-14 O-14C-Diffs 2 4 8 11 11 8 5 13 8 16 11 13C-Diff Rate 3.13 6.22 12.85 20.05 18.04 12.50 7.63 19.97 9.23 19.17 13.21 19.46

Rate# infections per 10,000 Pt Days

C-Diffs C-Diff Rate

C difficile infection (CDI)

C difficile and microbiology• Vegetative and spore forms

• Spores can remain viable up to 5 months on hospital hard surfaces• Resistant to cleaning and decontamination

• Fecal-oral• Inoculum can be as low as 10 spores

• Non-toxin and toxin-producing strains• Virulence factors are toxins A and B • Recent data suggests toxin B may be more potent that A

• Strains that are toxin A-/B+ more likely to be associated with severe and recurrent disease

Tamma et al JPIDS 2012

http://www cdiff support co uk/images/cDiffLarge jpeg

Spectrum of Disease• 20% CDI carriage rates in hospitalized children/adults

with diarrhea

Asymptomatic Carriage

Severe Disease

Sammons et al JAMA Pediatrics 2013

Mild/Moderate Disease

Clinical disease

Samady et al J Hosp Med 2013, epublished; Sammons et al JAMA Pediatrics 2013

Stool >3 stools/24 hoursLoose, watery (88%), bloody, mucous, fecal leukocytes

Clinical Fever, dehydration, abdominal distension/pain, ileus, pseudomembranous colitis

Severe (0-12%): sepsis, pleural effusion, toxic megacolon, perforation, ascites, pneumatosis, rectal prolapse, death

Laboratory Leukocytosis, albumin creatinine

Severe C difficile disease• Pseudomembranous colitis

• Endoscopic and histologic diagnosis• Associated with severe disease in adults

• Rare in children• Few case reports in neonates and younger infants and children

• Severe CDI• One multicenter cohort evaluating CDI in hospitalized children

• Colectomy rate of 1.3%, all cause mortality 4%• Another two center retrospective analysis

• ICU admission within 2 days of diagnosis (17%)• 2% of the cohort had toxic megacolon, perforation, surgical intervention

Kim et al Peds 2008; 133: 1266 Kim et al PIDJ 2012 31: 134

Worse outcomes• Retrospective nested case control study

•Pediatric patients with CDI compared to matched hospitalized patients

• Difference in length of stay higher• Community onset 5.6 days• Hospital onset 22 days

• Mortality of hospital onset disease higher (OR 6.7 95% CI 3.8-12)

• Higher cost• Community onset $19,000• Hospital onset $94,000

Sammons et al CID 2013: 51; 1

Rare Extraintestinal Manifestations• Bacteremia• Enteritis• Peritonitis• Appendicitis• Wound infection, cellulitis, abscess• Brain abscess• Septic joints, osteomyelitis• Reactive arthritis

Mattila et al, CID 2013

C difficile and pathogenesis

Tamma et al JPIDS 2012

Background: EpidemiologyRisk Factors

• Antimicrobial exposure• Acquisition of C. difficile• Advanced age• Underlying illness• Immunosuppression• Tube feeds• ? Gastric acid suppression

Main modifiable risk factors

Additional risk factors• Risk factors

• Proton pump inhibitors • Prolonged NG tube• Gastrostomy/jejunostomy tube• GI surgery• Repeated enemas• Use of diapers

• Underlying diagnoses• Underlying bowel disease, inflammatory bowel disease• Immunocompromised, impaired humoral immunity• Renal insufficiency

Tschudin-Sutter et al, CID 2013; 57: 1665Sandora et al, PIDJ 2011; 7: 580Samady et al J Hosp Med 2013, epublished

Which antibiotics are associated?• All antibiotics are associated with CDI

• 35-75% with CDI have antibiotic exposure• CDI usually occurs during or shortly after antibiotic exposure

• Can occur as long as 2-3 months after antibiotic exposure• Colonization and infection can occur after single dose of antibiotics

Tamma et al JPIDS 2012; Privitera et al Anitmic Agents Chemotherap 1991; 35: 208; Carignan et al CID 2008; 46:1838

Not all antibiotics are the sameAntibiotic Odd Ratio 95% CIPenicillin combinations 1.5 1.1-2.0

Clindamycin 2.9 2.0-4.0

Cephalosporins3° 3.2 1.8-5.7

2° 2.2 1.5-3.4

4° 2.1 1.3-3.5

Carbapenems 1.8 1.3-2.4

Quinolones 1.7 1.2-2.4

Trimeth-sulfa 1.8 1.0-3.0

Adapted from Slimings et al J Antimic Chemother, 2013; epublished

Prevention Strategies

Prevention Strategies

• Core Strategies•High levels of scientific evidence

•Demonstrated feasibility

• Supplemental Strategies

•Some scientific evidence

•Variable levels of feasibility

Prevention Strategies: Core

• Implement an antimicrobial stewardship program

• Contact Precautions for duration of diarrhea• Hand hygiene in compliance with CDC/WHO• Cleaning and disinfection of equipment and environment

• Laboratory-based alert system for immediate notification of positive test results

• Educate about CDI: HCP, housekeeping, administration, patients, families

http://www.cdc.gov/ncidod/dhqp/id_CdiffFAQ_HCP.htmlDubberke et al. Infect Control Hosp Epidemiol 2008;29:S81-92.

Prevention Strategies: Supplemental

• Extend use of Contact Precautions beyond duration of diarrhea (e.g., 48 hours)*

• Presumptive isolation for symptomatic patients pending confirmation of CDI

• Evaluate and optimize testing for CDI• Implement soap and water for hand hygiene before

exiting room of a patient with CDI• Implement universal glove use on units with high

CDI rates*• Use sodium hypochlorite (bleach) – containing

agents for environmental cleaning

* Not included in CDC/HICPAC 2007 Guideline for Isolation Precautions

Supplemental Prevention Strategies: Rationale for considering extending isolation beyond duration of diarrhea

Bobulsky et al. Clin Infect Dis 2008;46:447-50.

Supplemental Prevention Strategies: Hand Hygiene – Soap vs. Alcohol gel

• Alcohol not effective in eradicating C. difficilespores

• However, one hospital study found that from 2000-2003, despite increasing use of alcohol hand rub, there was no concomitant increase in CDI rates

• Discouraging alcohol gel use may undermine overall hand hygiene program with untoward consequences for HAIs in general

Boyce et al. Infect Control Hosp Epidemiol 2006;27:479-83.

Supplemental Prevention Strategies: Hand Washing: Product Comparison

Product Log10 Reduction

Tap Water 0.764% CHG antimicrobial hand wash 0.77Non-antimicrobial hand wash 0.78Non-antimicrobial body wash 0.860.3% triclosan antimicrobial hand wash 0.99Heavy duty hand cleaner used in manufacturing environments

1.21** Only value that was statistically better than others

Edmonds, et al. Presented at: SHEA 2009; Abstract 43.

Conclusion: Spores may be difficult to eradicate even with hand washing.

CDI and Infection Prevention

Johnson et al Am J Med 1990; 88: 137

Most important source of transmission of pathogens in the hospital setting

Healthcare worker hands

Glove up and wash your hands with soap and water after contact with CDI patient

C difficile and the Environment• Spores resist desiccation and persist up to

•5 months on hard surfaces•Patients in room previously occupied by CDI patient at higher risk for acquisition

•Room contamination • 49% in CDI rooms, 29% in asymptomatic carriers

•Highest areas of contamination bedrails and floor• Spores difficult to eradicate

•Sodium hypochlorite kills spores best cleaning agent

•Spores resistant to alcohol and ammonium based products

UV Light Disinfection (Xenex System)• UV light denatures DNA• Active against C difficile

Associated with decreased HAI CDI rates

Levin et al Am J Infec Control 2013

Measurement: Process Measures

• Core Measures:•Measure compliance with CDC/WHO recommendations for hand hygiene and Contact Precautions

•Assess adherence to protocols and adequacy of environmental cleaning

• Supplemental Measures:• Intensify assessment of compliance with process measures

•Track use of antibiotics associated with CDI in a facility

Diagnosis• Optimal testing algorithm for pediatric CDI unclear

• Diarrhea (≥3 stools/24 hours that take shape of container)

Brecher et al CID 2013; 57: 1175

The smell of C difficile: urban legend or truth?

Burdette and Bernstein, CID 2007; 44: 1142

• Nurse surveyed n=138 at the time of stool collection• Test characteristics of an odiferous diagnosis

• Sensitivity 55%• Specificity 83%

C difficile smelling beagel

Bomers et al, BMJ 2012; 345: e7396

• How do dogs compare?• Diagnosis from stool samples

• Sensitivity 100%• Specificity 100%

• Detection rounds on ward• Sensitivity 83%• Specificity 98%

C difficile testingTest Detects Sensitivity Specificity Use for

test of cureELISA for glutamatedehydrogenase

Organismonly

>94% 60-70% No!

Enzymeimmunoassay

Toxin A and B 30-94% 75-100% No!Toxin excretion 2wks 15-25%

4wks 5%NAAT/PCR Gene toxin A

and/or B85-95% 90-99% No!

Interval >4 weeks since last testing

GDH/EIA and PCR

68-100% 100% No!

Brecher et al CID 2013; 57: 1175: 1209; Tamma et al JPIDS, 2012; 1: 230

Surveillance Definition• Recurrent CDI

• >2 weeks and ≤8 weeks after most recent CDI

• Healthcare Facility• Stool collected >3 days after admission to the facility

• Community Onset• Stool collected from an outpatient ≤3 days after admission

• CO Healthcare Facility Associated• Meets community onset definition and discharged from facility ≤4 weeks prior to stool collection

http://www.cdc.gov/nhsn/acute-care-hospital/cdiff-mrsa/

C difficile and chlorhexidine gluconate (CHG)• Chlorhexidine not sporicidal but active against vegetative

cells and inhibits spore germination• Quasi experimental 19 mo

study in academic center • Reported CDI RR 0.71 for 3x/week CHG and RR 0.41 for daily CHG compared tobaseline

Rupp et al ICHE 2012

Summary• C difficile infection is increasing in US• Risk factors: antibiotics, hospital exposure• Prevention strategies:

• Identify early w >3 stools/24 hours• Soap & Water• Contact precautions for hospital stay• Bleach & UVC disinfection• CHG bathing

• Diagnosis:• PCR• Do not test for cure

Questions?

Treatment• Differentiate asymptomatic carriage and infection

•Stop/narrow broad spectrum antibiotics if possible•Stop antiperastaltic medications

• Pediatric treatment recommendations based on adult studies

• Metronidazole (PO, IV)• Vancomycin (PO)• Additional agents

• Rifaximin, nitazoxinide, fidaxomicin

Treatment

Episode Categorization Treatment Adult maxInitial Asymptomatic Consider no therapy

Mild/moderate Metronidazole30mg/kg/day 10-14 days

500mg PO TID

Adapted from Tamma et al JPIDS 2012

TreatmentEpisode Categorization Treatment Adult maxInitial Severe: electrolyte

disturbance, lab disturbance WBC >15 or <5, Cr, pseudo-membranous colitis

Oral vancomycin 40mg/kg/day in 4 doses for 10-14 days

125mg q6hr

Severe complicated (hypotension, toxic megacolon, perf, colectomy, ICU admit)

Oral vancomycin 40mg/kg/day in 4 doses for 10-14 days + metronidazole IV

Vanco PO500mg q6hr

Metro IV500mg TID

Adapted from Tamma et al JPIDS 2012

Oral Metronidazole vs. oral vancomycin

Kelly et al NEJM, 2008; 350 adapting data by Zar et al CID 2007l 45: 302

Oral Metronidazole vs. oral vancomycin

Kelly et al NEJM 2008; 359:18

Additional CDI treatment considerations

• Probiotics• Inconclusive evidence

• IVIG• Anecdotal evidence for severe, recalcitrant cases

• Fecal transplants• Promising experience with fecal transplants

van Nood et al NEJM, 2013; 368: 408

CDI Recurrence• Recurrence occurs within 8 weeks after the prior episode, if

symptoms resolve in the interim• Up to 25-30% of children develop a recurrence• Occurs due to relapse of original strain vs exposure new strain

• Retrospective pediatric study n=175 patients• Recurrence rate 12% • Mean time to recurrence 34 days (range 11-58 days)

• Risk factors• On antibiotics during initial CDI treatment course• No association found between vancomycin vs metronidazole, nor NAP1 strain

Tschudin-Sutter et al PIDJ 2013, epublished

Treatment of CDI recurrence• Optimal management not established in children nor adults

•Options include• Initial recurrence

•Repeat initial therapy for 10 days•If severe recurrence: Go from metronidazole to oral vancomycin

•Second recurrence•Taper or pulse oral vancomycin regimens

Additional treatment considerations: CDI recurrence•Rifaximin

• Nonabsorbed• Small case series in adults treated with rifaximin 20 days after completing standard therapy showed decrease recurrence (20% vs 50%)

• Concern for development high level resistance•Nitazoxanide

• In adults produces cure and relapse rates similar to vanco/metronidazole

•Fidaxomicin • Approved in >18 yrs in May 2011• Noninferior to vancomycin, significant reduction CDI recurrence in non-NAP1 strains

Antibiotic Mechanism of Action Absorbed (Y/N)

Patients

Rifaximin Rifamycin—inhibit transcription by bind to RNA polymerase

Oral vancomycin followed by rifaximin may be effective for recurrent disease

No Approved for children ≥12 years

Nitazoxanide Possibly interferes with electron transfer chain through interference with pyruvate:ferredoxin oxidoreductase

In adults produces cure and relapse rates similar to vanco/metro

Yes, converted into tizoxanide

Approved for children ≥1 year

Fidaxomicin Macrocyclic antibiotic that inhibits RNA polymerase

Minimally disrupts other GI flora, Noninferior to vancomycin, significant reduction CDI recurrence in non-NAP1 strains

No Approved for patients ≥18 year

CDI and antimicrobial stewardship• Critical to reduce CDI at the hospital level

• CDI rate reduction shown with • Programs that restrict clindamycin• General antimicrobial stewardship programs • In outbreak settings

Carling et al. ICHE 2003;24:699-706 Climo et al. Ann Intern Med 1998;128:989-95Khan et al. J Hosp Infect 2004;54:104-8 Pear et al. Ann Intern Med 1994;120:272-7 Bradley et al. J Antimicrob Chemother 1997;40:707-11

Valiquette et al, CID 2007;45:S112

ASP program

CDI and Infection Prevention

Johnson et al Am J Med 1990; 88: 137

Most important source of transmission of pathogens in the hospital setting

Healthcare worker hands

Glove up and wash your hands with soap and water after contact with CDI patient

What cleaning product is most efficacious against C difficile spores?

1) Quaternary ammonium wipes 2) Antibacterial soap and water 3) Sodium hypochlorite (bleach)

Thank you!

Ronald Reagan Medical Center• Environment

• Two Xenex machines• Rolled-out September, 2012• Used for C difficile discharge• From January 1-November 30, 2013

• Total N= 5,882 uses • ICU specific: 1,029 (17%)

• Black light room cleaning inspections

C difficile and Infection Prevention• Nurse driven testing and isolation

protocol• Identify high risk patients

• Exposure to antibiotics, healthcare settings

• Immunosuppressed

• GI surgery, PPI exposure

• Assess for signs• 3 or more unformed stools/24hr

• Abdominal pain/discomfort

• Place on isolation precautions & send test

• Do not restest once positive

• No test of cure

Ronald Reagan Medical Center• Hand Hygiene• Chlorhexidine treatment in all ICU patients >2 months• Antimicrobial Stewardship Program (ASP)

• Adult ASP since 2010• New pediatric ASP since March 2013

Pooled CDI Rates$, ICUs and ACUs RRUCMC, 2012-2013

$All rates are CDI rate per 10,000 patient days1CDPH Target Rate = 9.4/10,000, http://www.cdph.ca.gov/programs/hai/Documents

14.17

8.32

2.83

16.20

5.59

16.42

22.25

13.62

19.00 19.58

8.05 8.42

19.87

7.819.58 9.21

5.88

10.30

13.87 14.0512.13 11.51 12.07

2.290

5

10

15

20

25

30

Rate per 10,000 pa

tient days

C. difficile Infection Rate by Month

ICU

NONICU

NAP1/B1/027 Strain and concern for worse outcomes

Suh et al. 2008 SHEA. Abstract 306 Courtesy Romney Humphries, UCLA microbiology

Case, continued • 8yo M with a history of ALL has been admitted for 7 days with

fever and neutropenia when he develops copious diarrhea with abdominal pain. The stool is nonbloody. The child is on Day#7 of cefepime.

• The child has a positive C difficile testing and is started on metronidazole. 2 weeks later the child has recurrence of their diarrhea

• What is your differential diagnosis?• What additional tests would you send?• Would you start additional CDI-directed antibiotic treatment?

Change in test characteristics

Khanna et al, CID 2013; 56: 1401

Proportion pediatric patients receiving vancomycin has increased

Schwenk et al, Antimic Agents Chemo; 2013: 57: 4307